Senate Armed Services Committee Chairman Carl Levin (left), Michigan Democrat, and Sen. Roger Wicker, Mississippi Republican, talk on Capitol Hill in Washington on April 17, 2013, before a hearing with Defense Secretary Chuck Hagel. A letter addressed to Wicker, believed to be poisoned with ricin or a similarly toxic substance, was intercepted at a mail facility outside the capital earlier in the week. Levin issued a statement saying an aide in his Saginaw, Mich., office had also received a suspicious-looking letter. (Associated Press)